PESHAWAR/BANNU - A bomb claimed by the Taliban martyred 20 soldiers and wounded 30 when it ripped through a military convoy Sunday morning near Bannu cantonment area.Local sources and security forces said that explosion occurred when the convoy was almost ready to leave for North Waziristan Agency, which still has a strong presence of militants.Pakistan army helicopters later, in apparent retaliation, fired missiles at a road in the village of Musaki situated in the same tribal region killing three militants, intelligence and civil administration officials said.One of the missiles reportedly struck a nearby house, killing a five-year-old girl and a seven-year-old boy, according to a local administration official, although security officials could not confirm the civilian casualties.The Bannu bombing came at 8:45am, according to a senior military official, who said a vehicle-borne improvised explosive device caused the blast. The bomb hit one of the civilian vehicles that military had hired to move the troops.The intensity of the blast was so high that it jolted almost the whole of Bannu city. Body parts and soldiers' personal belongings littered the scene. Some of the body parts of the victims were found many yards away from the site while blood and human flesh was spread all around. The blast also damaged two other vehicles and a nearby house.After the blast army rescue squad and local people rushed the site and shifted the injured to Combined Military Hospital (CMH), Bannu. Emergency was declared in the hospital while some of the wounded security personnel were stated to be in critical condition.Heavy contingent of security forces cordoned off the area. Our correspondent said that as the journalists visited the site, security forces imposed curfew and did not allow anyone to enter the cantonment area. The Inter Services Public Relation (ISPR) confirmed killing of 20 persons and injuries to 30 others, but it did not reveal the names of those martyred.The banned outfit of Tehreek-e-Taliban Pakistan (TTP) claimed responsibility for the attack and termed it a revenge of their slain leader Hakimullah Mehsud. They said that Mehsud Brigade of Taliban carried out the attack. In a statement, Taliban spokesman Shahidullah Shahid said Taliban leadership is ready for dialogue if governments demonstrate sincerity and honesty in their intentions.KPK Chief Minister Parvez Khattak strongly condemned the bom-bing and termed it a barbaric incident of terrorism. He expressed symphonies with families of the martyred soldiers and prayed for the departed souls. Awami National Party Central President Asfandyar Wali Khan also condemned the incident and urged the government to take concrete steps to control the growing incidents of terrorism in the province.Prime Minister Nawaz Sharif decided to cancel his visit to Davos, Switzerland in wake of recent spike in terror incidents, especially the Bannu tragedy. He was scheduled to attend the annual summit of World Economic Forum (WEF) in Davos. "Our nation is united against extremism and terrorism and the sacrifices rendered by our citizens and personnel of law enforcing agencies will not go in vain,” PM Nawaz said in message issued from Islamabad, strongly condemning the Bannu attack.Hours before the announcement, Imran Khan, whose Pakistan Tehrik-i-Insaf is leading a coalition government in KPK, criticised Prime Minister Nawaz Sharif for his foreign visits amid escalating violence in the country. It was second blast in Khyber Pakhtunkhwa in four days as earlier a Tableeghi Markaz in Peshawar was targeted by unidentified terrorists.Agencies add: The civilian government led by Sharif, who came to power after elections last year, has said it is seeking talks with the Taliban. But so far little progress has been seen and terror attacks rose 20 percent in 2013 according to the independent Pakistan Institute for Peace Studies. Pakistan, which joined the US-led "war on terror" in 2001, says more than 40,000 people have been killed in the country since then by militants who oppose Islamabad's US alliance.Talat Masood, a retired general and security analyst, said recent assaults on the army were "testing the patience of the military" and were "extremely demoralising". Masood said the government's policy was creating frustration within the army. "It is becoming so evident to people that the government is so ineffective and paralysed and has no policy or strategy, while the army's hands are tied and it is being targeted and not being allowed to take action."The country’s troops have for years been battling the Taliban and other insurgents in the tribal belt next to the Afghan border. The army's headquarters in Rawalpindi came under attack in 2009, while major naval and air force bases have also been targeted in battles that have lasted for several hours. A senior Pakistani general was killed in a blast last September along with two other soldiers in an attack claimed by the Taliban. In May 2011, 89 paramilitary troops were killed in an attack at a military academy in Charsadda.